The present invention relates to a transmission wheel and a transmission apparatus formed by said wheel, and particularly to a transmission wheel and the transmission apparatus formed by the transmission wheels applied in the elevating transport platforms and transmission platforms of cargo handling systems for aircraft.
In cargo handling systems, conveyer belt, transmission platforms and air cargo transportation loaders are generally involved, usually there are one or several transmission platforms in such a system. While in the process of cargo transmission, the platforms bearing containers or container plates are required to accomplish a plurality of transmission functions. For instance, a longitudinal transmission, a transmission in a linear direction, is the major direction in transmission movement; a lateral transmission, which is a left and right transmission movement, is inevitable in a transmission process; a rotating transmission or oblique transmission, for turning over the direction, is sometimes applied for adjustment of cargo situation; or carrying out above movements simultaneously. Consequently, to perform above movements, at least several sets of mechanisms are required in general platform design, i.e., a longitudinal transmission mechanism, a lateral transmission mechanism, and a rotating transmission mechanism. Most of air cargo transportation loaders in current use have several layers in structure to realize above functions, that is, when a longitudinal transmission is needed, a longitudinal mechanism is lifted; when a lateral transmission is needed, a lateral mechanism is lifted; and when a rotating transmission is needed, a rotating mechanism is lifted. Not only an extremely complicated mechanism is required in such a structure, but also because it is time consuming; the apparatus of prior art has a lower efficiency. At present, a better design is a HeliRoll 8 disclosed in U.S. Pat. No. 4,978,272 which is able to accomplish above operations, as shown in FIG. 1A. The transportation loader of the above-mentioned U.S. Patent has a transmission apparatus divided into several sets in a same plane, e.g. typically divided into four sets and has the HeliRoll 8 in two adjacent sets arranged oppositely in rotating direction so as to accomplish the above movements via mutual cooperation of the wheel sets, as shown in FIG. 1B; thereby the structure is greatly simplified. However the friction of such a HeliRoll 8 against the bottom of a container or plate is relative greater; on the other hand, it can be seen in the drawing that more than two sets of HeliRolls are required in cargo transmission along any direction for all transmission apparatus formed by the HeliRolls, which are power consuming. For example, when the sets of X1 and X2 or Y1 and Y2 rotating respectively in relative manner, the platform shall be transmitted along a direction of arrow YL or YR; and when the sets of X1 and Y1 or X2 and Y2 rotating in relative manner, the platform shall be transmitted along a direction of an arrow XB or XF. In addition, the above combination of wheels of the prior art tend to slip when the surface of the platform covering ice and snow.
It is an object of the present invention to provide a transmission wheel used for platform transmission; the transmission wheel can be used both for power transmission and for supporting a container or a container plate by several ball rollers mounted on both sides of a wheel frame.
It is a further object of the present invention to provide a transmission apparatus for platform transmission, the apparatus can make use of the transmission wheel both for power transmission and support purposes to realize transmission along a linear direction via the movements of a set of wheels.
In order to realize the above objects, the present invention provides a transmission wheel comprising a wheel frame centered with a hole, for fastening to a drive shaft and driving cargo, wherein at least two pivotable ball roller means are provided on the wheel frame, in which
at least the first pivotable ball roller means comprises several ball rollers which are arranged on several supports protuberated from the wheel frame respectively via its axis, and evenly arranged along the circle of circular are camber of each ball roller;
at least the second pivotable ball roller means comprises several ball rollers which are arranged on several supports protuberated from the wheel frame respectively via its axis, evenly arranged along the circle of circular arc camber of each ball roller and staggered with the several ball rollers of the first means.
A transmission wheel according to the present invention, wherein the wheel frame centered with a hole comprises a wheel disk which is provided between the first and the second ball roller means.
A transmission wheel according to the present invention, wherein the supports of the first and the second ball roller means are integrated with the wheel frame.
A transmission wheel according to the present invention, wherein a concave portion corresponding to the circular arc camber of each ball roller, located at the back of each ball roller, is provided on the wheel disk.
A transmission wheel according to the present invention, wherein all circular arc cambers of the several ball rollers which are evenly staggered on two pivotable ball roller means form a circle.
A transmission wheel according to the present invention, wherein a circular arc diameter formed by the several ball rollers is greater than that of the wheel disk.
A transmission wheel according to the present invention, wherein each pivotable ball rollers means is provided with three ball rollers.
A transmission wheel according to the present invention, wherein a length of circular arc camber of each ball roller is one sixth of arc length of the circle in the wheel disk.
A transmission wheel according to the present invention, wherein the length of circular arc camber of each ball roller is greater than one sixth of arc length of the circle in the wheel disk.
A platform transmission apparatus for transmitting on multiple directions comprising
a platform for bearing transmitted cargo;
a lift-up mechanism for lifting the platform to a suitable height;
a lateral transmission mechanism for lateral translation of the platform, comprising a plurality of motor-driven drive shafts on which a transmission wheel is provided by its wheel frame centered with a hole; and
a longitudinal transmission mechanism for longitudinal translation of the platform, comprising a plurality of motor-driven drive shafts on which the transmission wheel is also provided, wherein at least two pivotable ball roller means are provided on the wheel frame, in which
at least the first pivotable ball roller means comprises several ball rollers which are arranged on several supports protuberated from the wheel frame respectively via its axis, and evenly arranged along the circle of circular arc camber of each ball roller;
at least the second pivotable ball roller means comprises several ball rollers which are arranged on several supports protuberated from the wheel frame respectively via its axis, evenly arranged along the circle of circular arc camber of each ball roller and staggered with the several ball rollers of the first mean.
A platform transmission apparatus according to the present invention, wherein the wheel frame centered with a hole comprises a wheel disk which is provided between the first and the second ball roller means.
A platform transmission apparatus according to the present invention, wherein axes of the lateral transmission mechanisms and axes of the longitudinal transmission mechanisms are mutual perpendicularly installed.
According to an aspect of the invention, since several ball rollers are arranged along the circle of the wheel disk on both sides of a transmission wheel, it enables a transmission mechanism formed by the transmission wheels of the present invention to serve as a drive wheel taking the platform into action under motor driving; on the other hand, under unpowered condition, as a passive bearing wheel, can support a platform into action via a ball roller rotating around its self axis. Therefore, the present invention enables a container or container plate to be pressed a welldistributed force as the power is reasonably utilized, and the present invention avoid slippage occurred in transmission.
According to another aspect of the invention, since the above transmission wheel which is able to achieve both active and passive transmission has been employed in a transmission apparatus of the invention, the transmission mechanisms can be installed in a same plane. Thus it can be seen, adopting the invention, no complicated switching operation is needed, the structure is greatly simplified and raised the working efficiency; meanwhile transmission power being fully utilized, friction loss between a transmission apparatus and the bottom of the platform is reduced.